Brake for tramways and railways.



P. J.' PRINGLE. BRAKE FOR TRAMWAYS AND RAILWAYS.

LPPLIOATION FILED JULY 12, 1907. 956,826.

Patented May 3, 1910.

2 SHEETS-JESS! 1 P. J. PRI'NGLE. BRAKE FOR TRAMWAYS AND RAILWAYS.APPLIOATIONTILBD JULY 12, 1907.

956,826. I Patented May 3, 1910.

2 SHEETS-SHEET 2. m

PERGIVAL J. PRINGLE, 0F SIIDMOUTH, ENGLAND.

BRAKE FOR 'IRAMWAYS AND RAILWAYS.

Specification of Letters Patent.

Application filed July 12, 1907.

Patented May 3, 1910.

Serial No. 383,509.

To all whom it may concern:

Be it known that I, PEROIVAL J OHN PRIN- GLE, a subject of His Majestythe King of England, residing at Sidmouth, in the county of Devon andKingdom of England, have invented certain new and useful Improvements inBrakes for Tramways and Rail- Ways, of which the following is aspecification.

This invention consists of a mechanical form of brake for use, generallyin times of emergency.

It consists in utilizing the groove of the ordinary rail for the brakingsurface, either alone or in conjunction with some portion or all of theremaining top surface of the-rails.

I will now describe my invention with reference to the accompanyingdrawings which are more or less diagrammatic and show only so much ofthe. vehicle wheel and truck and rail as is necessary for elucidationand wherein Figure 1 is a side elevation showing the skid in theoperative position in full lines and in the inoperative position indot-anddash lines. Fig. 2 is a cross section of Fig. 1. Fig. 3 is a sideelevation of the skid illustrating a cleaning attachment therefor. Fig.4: is a side elevation of the skid in the inoperative position. Fig. 5is a side elevation showing in full and dot-and-dash lines two operativepositions of the skid. Fig. 6 is a side elevation of the skid combinedwith a wheel brake-block, and of means for operating them. Fig. 7 is aside elevation of another form of skid. Fig. 8 is a side elevation rep--resenting skids applied to both front and rear wheels. Fig. 9 is a sideelevation of an arrangement of combined skid and wheel brake block, thefull lines indicating the working position and the dot-and-dashlines theinoperative position. Fig. 10 is a side elevation representing onearrangement of combined skid and track brake block. Fig.

11 is a side elevation of another arrangement of combined skid and trackbrake block. And Fig. 12 is a side elevation of yet another arrangementof combined skid and track brake block.

Inone form I may employ a ta ered bar a of suitable material shaped to tc section of the rail groove 6, which normally is held in advance of oneof the rotating car wheels 0, with the tapered end OZ pointingtoward thewheel and parallel to the rail groove and just clear of same. This bar aatthe end remote from the tapered part at is suitably attached to thecar or car truck; at the same time the bar a as a whole, or some part ofit, can be given a longitudinal movement be fore its attachment canexert a direct pull on the car or truck.

There are some suitable means of quickly advancing the tapered bar athrough the longitudinal movement allowed it, and this movement is suchas will advance the tapered bar, normally clear of the wheel 0 and rail,to a position bearing upon the bottom of the rail groove 6 and directlyunder the wheel flange 6, so that the flange 6 will ride over thetapered bar a and transfer to same the weight of the car on thisparticular wheel 0. As soon as the weight of car wheel 0 is transferredto the tapered bar a and the revolving wheel locked, an immediate andpowerful longitudinal pull is exerted on same, so as to reduce theeffect of this sudden strain on the bar and its attachment to the car ortruck, a suitable form of spring, rubber, or other means acting'as abuffer, may be interposed in some portion of the bar a or at its pointof attachment. One method of advancing this tapered bar a is by means ofa lever acting directly on same and operated by the driver, or a springor other suitable means may exert a force to do this, and the releasingof this force be under the control of a hand or foot lever operated bythe driver. On the weight of the car being released from the taperedend, means are provided for moving the tapered bar a back to its normalpositlon, and in the case of the springor other means being used, theresetting of same so that the brake can be again applied when necessary.

The skid a is made of a tough quality of iron or steel and if softerthan the material of rail will bite the surface of same and give agreater co-eflicient of friction. The top face of skid a has a grooveformed in same as at f into which the flange e of wheel 0 drops. Theskid a is of such a thickness and is only allowed to travel sufficientlyfar under the wheel 0 so that the flange 6 does not become entirelyremoved fromthe groove '6. This fact, in addition to the groove 7 inskid a give ample guide to the flanges e and therefore provision againstderailment. The

sloping face 9 allows skid to rise over any obstructions in its path. Ifthis brake is used only on gradients, more or less steep, the railgroove 2) is generally free from much dirt and this design of skid awould besuitable. When howeverthereis' much dirt in the grooveespecially if this is in a hard dryish state, it becomes advantageous toget. i

5 the maximum braking efiect to clean the groove somewhat. To eiiectthis the skid; a, may be shaped as at h or a. cleaning strip fixed inadvance of skid wherever most convenient. The stripi shows one method.

By adopting the latter, should the skid, meet with any seriousobstruction such as run ning through a point,v the strip ibends upvwithout any dama eotherwise being done.

The position 0 skid when out of use, shown by dotted linesv aliows it toclear points and similar obstructions.

Ih ascending steep gradients it: may" be desirable fer the skid, w-to bedroppedhe fore the ascent. is made, and in? the event of the vehicle,or, vehicles running backward for the skid a" to come" automaticallyinto action. To. efiect this:- a third position is' given to the-skid asshown as 7', Fig: 4e.

' When the skid a is advanced or. releasedby the interposition; ofasprihg or other suitable means it would.) only advance as far as Thisprevents the skid tip at. pressingbymeans oifitsfuil weight on. thegroove su'rface b, and" so? aillbwit to suitablytrail behind the wheel 0when advancingup; the" gradient; 6n the vehi'cleor,vehicles-commen'ci'ng to" run back, the wheel flange e n'i'ps the skidasuiii'ciently and then draws it: into the position: shown" Fig; 1,distending the spring inso doing. This" has also the advantagethatsliould skid a' he. in, action when traveling through a pointi asatFig. 5, that as soon as the wheel flangee. effects no PIB'SSTII'BOIIthe skid. a-that tlie" sprin'g willpullloack the skid' as shown at k sothat. it" does not" get jammed against theedge l'o'f pointi Itis"preitirable to have. these skids 0,; either connected in pairs" or each.skid of thepair" separate from one. another but opera-ted fi'om the samesource. The two SkldSf'OI. pair: of" skids operate: on the two wheels ofone axle so* that the retarding force is about equally applied? on eachside of the car.-

There are means of adjustment: provided" sothat the skids a can: beadvanced when wear on them has occurred'or advanced ancl set Back sothat the weight of the car can be divided between the skids: andeaichoperate with approximately the same retarding IECI'GBL- M I By utilizingthe groove 6 as abraking sur facein the manner described I obtaina:

surface seriously affects the efliciency of othenbrakes. In my; brake,it is independent of tread condition.

When the tread 'i'svin a greasy condition, the dirt in the groove isgenerally soft and wet and the skid cuts through this and bears againstthe rail surface without materially affecting its .efliciency.

, The skid brake is not dependent on a sup- .ply of sand for itsefliciency.

In other methods of braking as general ly used; the skidding or lockingof wheels of vehicles means a great diminution of' the brakingpower; andin the case of electric. brakes: dependent for their electric poweronthe motor or motors revolved by the wheels, an entire cessation oi?the braking ower. The skid brake is independent of siiddedfor-lockedwheel's, in' fac-t its operation is to skid= orlock the wheels therebyutilizing this condition so dangerous to other: methods oi hraking:

The; skid Brake can be practically instanti'y applied and atits feltpower; The skid' brake can he arranged to automatically 9 0 operate on avehicle orvehicles running backward during the ascent of a gradient.

The skid mayi if desired": operate on a part or all of? the. remainderoithetop surface of therail inaddition to v the groove.

The tapered part of skid in.ad'ditimto being: shaped to the section ofthe-1 rail groove may be corrugated or= shaped in any special way toincrease the. coefficient 05E friction between it and thesurfaceof thegroove:

The attachment in 4? wheel 'l caremay loe' conveniently Inade- :tothe'axleofthe adjoinin-g pair-of'w-heelsor hy means ofa-hracketboltedto thetruck frame.

A; compact arranger-nentv as illustrated in- Fig; 6 complises a: bracketm attachedtb-the truck frame it" closely adjoining the wheel- 0 to-beoperated u'pon'. 'lliebracket m foraconvenientdistance toward the rail,follows thecurvature of the wheelie, and hasana'd justahlie; screw orscrew 0 fittedtheretoso tat the projectingends of same would be directedtoward and be almost in con-tact iw-ith' the tread" p: ofwheei. The tapered loar 1 l5 ctr-passes through a suitable hole g in the bot-- tomoi'bracket-m so that-it assumes the nor- *mal* position previously referredto: It couldbe' allowed the requisite longitudiiial .movement in thishole together with the-buf- Ifferand adjusting arrangeme nt beflire de-1 scribed:

By forming the bracket m inthe ahove' .manner* and causing the sideofisamead- ;joinin the wheel; to come in nearlyclose 1 contact, throughthe agency of the-serewr er screws *0, with the'tread of w iieei" p,-the strain and'puil ithrowni on tiapered iia-r w 'wlren the .ldrake' isoperated, is partly counteracted by; he screw-or screws 0 pressihgomthetreadt of wheel p (due to the springing of the bracket toward the wheelunder the strain) and so relieving the bracket m of a portion of thestrain.

Fig. (3 also shows a simple hand-operating means comprising a lever 1".By pulling lever 1" the skid a is advanced so that it will just bejammed by the wheel flange 6 as described in Fig. 4. On the wheel 0further revolving it will draw skid a right under wheel flange 6distending a spring .9 suitably.

The loop 23 of the spring 8 is of such a length that no pull is exertedagainst the stop a and therefore no distension of the spring takes placeuntil the skid is in the first jammed position referred to above.

Obviously a spring or other means may be so applied such as v so thatthe skid a may be advanced almost instantly. To effect this the lever 1"is loose from 'w and on pulling the lever 1" in the direction of thearrow, its stop-piece 22, moves to until it has got the other side ofdead center, when the spring U can exert its full power and almostinstantly apply the skid. To reset the skid the lever is moved in thereverse direction and'the stop piece y then forces to back to positionshown. The lock nuts 2 allow the screwed end of skid to be advanced orwithdrawn for adjustment purposes or to take up any wear on the skid.The nut z is cup-shaped and bears against a similar shaped recess 2 inbracket m. An india-rubber washer may be placed between these faces todeaden the blow. The hole 9 is slotted sufliciently for the skid toadjust itself to the varying diameter of the flange as it wears.

A mode of attaching to the adjoining wheel axle is shown in Fig. 7 whichexplains itself. Provision must be made for lubricating the bearing part3.

The advancing of the skids may instead of being operated by hand, beeffected automatically. One method might provide for the car wheels orthe car when travelin beyond a certain speed, operating the ski sthrough a suitable device.

Where it is required to give an emergency brake for the car traveling ineither direction, it may be necessary to provide skids operating in bothdirections. One form of this'isrepresented in Fig. 8. The skids may bearranged to act on the rear wheel only or they may be arranged to act onboth the front and rear-wheels.

Fig. 9 illustrates the combination with the skid a of a block 7 forbraking the tread of the wheel when the skid comes lnto operation.

The skids are attached to the car or car truck, and any pull there maybe on the skids is transmitted to this point of attachment. I mayutilize this pull on the skids to operate a further brake or brakes.

In one form I, as shown in Fig. 10, use

a bar 4, one end of which terminates in a bearing block 5 and is free torevolve around the axle 6 or some other equivalent portion, adjoiningthe wheel on which the skid a operates, and the other end is shaped inthe form of a shoe 7, and can, when desired, be brought to bear eitheron the groove 6 of the rail, or on some portion, or all of the remainingsurface of the rail, or on the two conjointly. VVhen-the bar 4 is incontact with the rail, it takes up a sloping position in advance of thewheel to be operated upon. The skid a is suitably held attached, orpivoled to this sloping bar as shown. Normally this bar 4 is revolvedaround its center 6 sufliciently to keep the skid a from being grippedby the advancing wheel. On lowering the bar in any suitable orconvenient manner, the skid a becomes drawn under whatever portion ofthe wheel it is arranged to be in contact with. The pull now exerted onthe skid a is transmitted to the sloping bar 4, and results in twoforces, one causing the shoe to be forced downward on to the rail, andthe other, to give an upward pressure against the axle or to whateverpart the bar may be pivoted. The surface and material of the shoe may beof any suitable substance and the front part of the shoe is rounded soas to have no tendency to catch in any part of the-rail system.Obviously as shown in Fig. 11, this bar 4 may revolve around a pivot 6attached to some suitable portion of the car or truck instead of theaxle as described. By suitably ar ranging the pivot of the bar 4longitudinally of the vehicle the weight of the car thereon may beregulated. The farther away the pivot of the bar 4 is from the axle 6the greater will be the proportion of the weight of the car utilized fordownward pressure on the skid a and shoe 7. For instance, if the car orvehicle is on a 4 wheel truck and the skid is arranged to operate on therear Wheel, the bar 4 may as shown in Fig. 12, be pivoted on to thefront axle of its equivalent 6, and the skid a connected thereto inthemanner previously described with suitable arrangements for advancing andre-' moving it from under the wheel. In this case the downward pressureexerted on the shoe would utilize a proportion of the weight on thefront axle, while the skid would utilize the whole of the weight on therear wheel and a more powerful braking effect would be obtained. I mayalso utilize the pull on the skid a to operate a brake block or blocksbearing on a wheel or wheels other than the one being skidded, and thesemay be the existing hand or power worked brake blocks or ones speciallyfitted, or, I may utilize the pullto operate the ordinary mechanicalslipper brake or one of a similar design specially fitted for thisurpose. In this latter arrangement, it may e preferable fer: the skid;auto be able-t0 immediately 0pe naztesthe slipper independently 013enemyv wrrangementsthere may-be fierrworking it by hand or power. Thehand or power applicaztioni could then be made to supplement thatfrom-the skid, or be used separately.

What I claim and desire to'seeure by Letters Patent oi the United:States is 1. The combination: with a Wheel 0i atramwwy 01"railwa-yrvehicleofa skid; brake fior' emanating; in, and with, thetmil'groove 0111y, andvmea;ns: fiorsopertvting; saidskld, for the punpesesspecified? 2. The combination with a Wheel of a:

trwmwzuyor railwwy vehicle, 01 5a bar shaped t0:- the genera-1 cientourof 131185 uppen'part of the railgroove-t0- 25611 with saidgreowe only asa, skid, and means tor: advancing and withdrawingsaidibar tewamd, vandfir'om, said whee1,..for the punposes speeifiedh 8z'T'heeombination witha skid brake c0.- ga-ctingzin', and with the wil move amd with ifiztWheel. of a; tramway or-rayi Way vehicle, of another brake blockoperated by, and from, ftheskid; 01 the purposes specified.

41 The combination Withzv skid brake 0Q- P. J. PRIEGLE.

Witnesses:

G; K. EDDOWES, BiQLLASON.

